Insecticide



Patented Sept. 26, 1944 UNITED STATES PATENT orrlcs 2,358,942 msEcricmE Edouard H. Siegler, Takoma Park Md.; dedicated I to the free use of the People in the Territory of the United States No Drawing. Application January 7, 1944,

, Serial No. 517,377

- (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 75 7) 2 Claims.

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

I hereby dedicate the invention herein described to the free use of the people in the territory of the United States to take effect on the granting of a patent to me.

This invention relates to the pronounced synergistic action which is obtained when 2,2-bis(parachlorophenyl) -l, l,1-trichloroethane is mechanically added in a small amount to a standard dosage of lead arsenate. When used alone, neither 2,2- b i s(parachlorophenyl) -1,1,1--trichloroethane phenyl) -1,1,1-trichloroethane with lead arsenate,

I plug method in which each plug was infested nor lead arsenate, in the dosages employed, effects I a high degree of mortality of newly-hatched codling moth larvae Carpocapsa pomo'nella (L5. But, when these compounds, at the same dosages, are mixed and applied together, they produce an insect mortality which is significantly greater than that efiected by a simple summation of the mortalities as obtained when the compounds-are used independently of each other. In other words, a

distinct synergistic or additive effect is obtained as a result 0! intimately mixing these compounds for insecticidal usage.

Insecticidal compositions prepared according to my invention also effect a substantially even distribution over the host plant of the insecticidal ingredient which is used in the lesser quantity, namely, 2,2-bis(parachlorophenyl)-1,l,1-trichloroethane. This result is accomplished through the use of lead arsenate as a diluent for 2,2- bis(parachlorophen'yl) -1,1,1-t r i c h l o r o ethane. Through the admixture of these compounds, a homogeneous composition is obtained whereby 2,2- bi s(parachlorophenyl) -1,1,1-trichloroethane is distributed as evenly as possible within the limits of the quantities employed.

Moreover, my insecticidal compositions are persistent and cause 2,2-bis(parachlorophenyl) 1,1,1-trichloroethane to adhere more thorou h y to the host plant. This residual effectiveness results from the admixture of 2,2-bis(para'chlorophenyl) -1,1,1-trichloroethane with lead arsenate which possesses excellent adhesive properties and 0 compatible liquid might be used as well.

Table Number Percentage Spray materials and dosage of a pple oi insect (poundsgauons) plugs mortality 2,2-bis(parachiorophenyl)-l,1,l-trichloroethane, 34-100 96 78 Lead arsenate, 4-100 103 54 2,2-bis(parachloroplienyl) -1,l,1 -trichloroethane, 34-100, plus lead arsenate, 4-100 92 Check (untreated)... .l 97 3 is in addition insoluble in water. Lead arsenate, therefore, protects 2,2-bis(parachlorophenyl) 1,1,1-trich1oroethane when used under outdoor conditions against its removal from the host plant by rain, dew, wind, and so forth.

As an example of thesynergistic insecticidal action produced by mixing 2,,2-bis(paraohlorosome typical results of tests against newly hatched codling moth larvae are given in the table below. These data were obtained by means of the applewith a larva. Although the codling moth is used as an example, this invention is not limited to this insect, nor is it restricted to the quantities of the components as given herein.

From the foregoing table, it will be seen that neither 2,2-bis (parachlorophenyll-1,1,1-trichloroethane nor lead arsenate, when used separately, produced/a very high percentage of mortality. But when these compounds were mixed and applied together as an insecticide there was 100 percent mortality'as a result of synergistic action.

The insecticidal spray compositions illustrated in the table above were prepared in water. It should be understood, however, that any other Having thus described my invention, I claim: 1. An insecticidal composition comprising 2,2- bis(parachlorophenyl) -1,1,1-trichloroethane and lead arsenate.

2. An insecticidal spray composition comprisin g 2,2-bis(parachlorophenyl) -1,1,1-trichloroethane and lead arsenate in a compatible liquid.

EDOUARD H. SIEGLER. 

